Developed by extinct Genocide Beetle bioengineers as living musical instruments, able to record and produce all manner of sounds with complex auditory organ atop cone. After fall of Beetle civilization the echolaliacs went feral, vowing to forevermore produce music only for their own edification, becoming a successful predator of Underworld humanoids

Able to sustain itself on variety of protein sources but ideal diet consists entirely of human-like creatures due to Beetle policy of breeding scads of experimental humanoids and utilizing those unfit for other duties as feed animals for their other enslaved monstrosities

Uses bits of previously recorded conversations (renewed habitually during periods of inertia between meals) to lure humans into striking distance of sonic stun wave (60'): calling out for aid, begging for respite from terrible loneliness, offering rare objects for sale, inquiring about the daily news, etc. etc. Syntax and appropriateness will be approximate at best. If PCs attempt to engage the echolaliac in conversation, sooner or later it becomes obvious that they speak with an idiot trying to hide the fact that it has no idea what its talking about, a realization often enough made far too late.

When inert, echolaliacs curl up their musical organs and attempt to blend in with the stalagmites

At need, able to take in enormous volumes of air into its body cavity via the musical organ atop its cone, swelling to gross immensity before blasting forth a powerful gust of reeking breath from its mouth lasting several seconds during which it may be aimed in multiple directions. Anything human-sized caught in this surge of unpleasantness, barring firm anchoring or extreme good fortune, is tossed about helplessly for 2-40 feet of random smashing into things

After a fulfilling meal of human flesh, echolaliacs turn to their secondary passion and emit highly complex and subtle symphonic compositions of stirring, eerie majesty that echo through the Underworld, providing involuntary musical entertainment for denizens within a 5 mile radius. These performances last until the creature becomes hungry once again, after 2d12 hours

Underworld humanoids sometimes dare to draw out conversation with echolaliacs, remaining carefully outside the range of their sonic stun ability, in an effort to glean information overheard in the recent past

Echolaliacs think plain strider songs are fine, if you like children's music

Treasure: Interesting indigestible items may sometimes be found in great pools of vomit near echolaliac territories (their sole means of eliminating waste)

Created as a prototype construction slave by the Beetles for their aborted deep space exploration/colonization project but discontinued due to budgetary concerns incurred by perpetual Genocide Wars and set to work in the Underworld

Able to survive indefinitely due to self-renewing depleted Chaos metabolism, immune to poisonous gases, highly resistant to magic and environmental factors such as heat, cold, vacuum

Stupendous physical strength, able to fold up limbs as accordion as convenient, powerful hands and feet act as multi-tools able to cut stone, act as clamps, drive spikes, etc.

Luminous eyes project light of variable intensity up to a distance of 240'

In addition to keeping paleogean Beetle architecture in tip-top condition, occasionally seized by wistful yearning for new project and can be highly suggestible during these vulnerable periods

Able to perceive and communicate with even the most intangible ghost Beetles still stalking the Underworld (typically haunting ancient dwellings, temples, and laboratories) and always obeys their commands

Fears and loathes most humanoids due to centuries of accumulated evidence of their inherent treachery and unpredictable irrationality and will attempt to avoid most contact unless in dire need of work materials

If somehow engaged in communication, refers to self as The Custodian, able to provide vague hints about Underworld history, but exclusively through the lens of a deep and abiding interest in architecture and little else

Treasure: Heaps of costly building supplies if encountered when engaged in project, otherwise nil

When a colossal roaming plume of depleted Chaos and other weird industrial pollutants settled temporarily on their northern village, all but those possessing the hardiest constitutions died instantly or were subject to terrifying and ultimately deadly mutations. Those mighty few who survived were transmuted to giant size, their minds stupefied and permanently confused by this transformation. Giant barbarians share an irresistible urge to descend into the Underworld and quest in the vain hope they might find some escape from their fate, bolstered by a shameful realization that they no longer belong among surface people.

Any combat triggers uncontrollable berserk frenzy lasting until all enemies are smashed (5% chance of fatal heart attack per battle), followed by a equal period of inert perspiration

Instinct and weird sense of propriety pits the giant barbarian against the many Underworld godlings seeking self-aggrandizement in the depths of the earth

Sometimes make rough encampments just outside of major population areas, where they sell their considerable martial skills to the highest bidder, simultaneously holding all parties in equal contempt

Treasure: Giant barbarians tend to get drunk and spend booty (frivolously) almost as soon as they acquire it so if you catch them at precisely the right moment they could be loaded down with cash and prizes, otherwise they are broke.